(1) Field of the Invention
This invention relates to the securing and positioning of a Bowden cable.
(2) Prior Art
As is known, a Bowden cable is a wire made of spring steel which is enclosed by helical lay wires and used to transmit longitudinal motions over distances, particularly around corners. Assembly and adjustment of a speed control device for maintaining a given speed of an automobile requires that during manufacture of the automobile and adjustment wire be quickly and accurately positioned to establish a predetermined setting. Various clamp means are known to secure a Bowden cable to another member. For example, a clamp having a semicircular grasping portion can fit over a portion of the outside of the Bowden cable. The clamp can have an extension with an opening for passing a screw to attach the clamp to a support member. Such a clamping method is undesirable because it depends on the frictional force between the clamp and the exterior of the Bowden cable to secure the longitudinal position of the Bowden cable. Any slippage between the Bowden cable and the clamp results in a misadjustment of the Bowden cable. Additionally, if the clamp is too tight, the function of the Bowden can be impaired because the internal wire is prevented from movement.
In another known clamp means, a nylon sleeve covering of the helical lay wires has a threaded portion. Two adjacent ring-like bracket pieces for mounting are each threaded over the end of the cable and then pressed together around the threads. A press fit secures the bracket pieces to each other and to the threaded portion. A drawback of this particular configuration is the need for threading or insertion of the bracket pieces over the end of the cable. Another disadvantage is the longitudinal movement of the mounting bracket with respect to the sleeve when the mounting bracket is turned on the threads of the sleeve. Not only would easier assembly be more desirable, but it would be desirable to eliminate longitudinal relative motion between the clamp and the cable. The ring-like bracket pieces also have a mounting configuration which constrains them to be positioned at the end of the Bowden cable.
Apart from the securing of a Bowden cable, longitudinal adjustment of the central wire of a Bowden cable has been attempted by the use of a bead chain. Thus, depending upon the position desired, a particular bead of the chain can be secured within a keyway as is well known. This approach is also undesirable because each bead increment provides a relatively large step in the adjustment length and because of the additional complexity of attaching the ball chain at the end of the central wire. These are some of the problems this invention overcomes.